ScyllaDB Open Source Release 4.0.4

ScyllaDB Open Source 4.0.4 is a bugfix release for the ScyllaDB 4.0 stable branch, offering backward compatibility and support for rolling upgrades, although an upgrade to the latest ScyllaDB 4.1 is recommended. The release addresses several issues, including fixing problems with CQL where default TTLs are reset and unrecognized entity exceptions occur, as well as storage issues like the SSTable upgrade's increased disk space requirement. It also resolves user experience errors, such as a serialization error in scylla-housekeeping and traceback occurrences in scylla_setup, and enhances stability by addressing issues like unbounded internal concurrency in counter write operations and incorrect results or crashes during reverse queries with multiple IN restrictions. Performance improvements include addressing the needless retention of tombstones in local system tables, which could lead to read timeouts.